The pharmacokinetics and safety of epigallocatechin gallate and a characterized, polyphenolic mixture will be evaluated in normal, healthy volunteers after a single administration. Five subjects will be evaluated at each of 4 doses for both products. Based on pharmacokinetic and safety results, a 3-month, repeat-dose study will be conducted with both products. Eligible subjects will be at high risk for the development of epithelial cancers. Plasma EGCG levels and pharmacological modulation of biochemical endpoints will be evaluated.